tryActivate
Attempts to activate the skill, reporting whether it actually fired.
A skill with its own gating condition (for example "target below 30% health") returns false when that condition fails. The caller then consumes neither the cooldown nor the damage bonus, so the condition genuinely governs the skill. Without this, a caller can only invoke onActivate and has no way to learn whether anything happened — which previously let gated skills apply their damage bonus on every hit, bypassing their own condition entirely.
Skills that always fire when off cooldown need not override this.
Return
true if the skill actually fired
Parameters
player
The player activating the skill
event
The triggering event (can be null)